Mass retraction movement of the anterior upper teeth using orthodontic mini-implants as anchorage

Background: Several studies have demonstrated the application of mini-implants in the orthodontic treatment as anchorage during the retraction movement of the anterior teeth. Purpose: This study was designed to evaluate the mass retraction movement of the anterior upper teeth using orthodontic mini-implants as anchorage. Materials and methods: Nine patients with class I malocclusion and Angle's class II, needing extractions of the upper first premolars, were enrolled in this case series. The retraction was performed using sliding mechanics and orthodontic anchorage on mini-implants. Measures were taken by initial and final cephalometric X-rays of the retraction movement to evaluate whether the mini-implants remained stationary and displacements of the incisors and the upper first premolars. Results: Out of 18 mini-implants, 8 mesialized (0. 45 mm, average) and 3 extruded (0. 14 mm, average). The upper incisors were retracted on the average of 4. 21 mm, extruded 0. 33 mm, and tipped 10. 3°. There were no statistical significant modifications in the placement of the posterior teeth. Conclusions: Although there was a very small displacement of the mini-implants, they still provided an adequate anchorage for the retraction of the anterior teeth, and there was no loss in the anchorage of the posterior teeth. © 2011 Springer-Verlag.